Doctor Strange
Doctor Strange marked an important shift in tone for the MCU, introducing the concept of magic to a science-based universe that had traditionally avoided the supernatural. Marvel worked hard in order to ensure magic was integrated seamlessly though; the movie touched on everything from string theory to quantum mechanics.
2015 had seen Marvel Studios separated out from the wider Marvel group in an organizational restructure that essentially limited the importance of Marvel’s CEO Ike Perlmutter. The build-up to Doctor Strange, though, showed that the separate companies could still work together closely; prelude tie-in comics were strong, and the drip-feed of information about the film was perfectly co-ordinated with the tie-ins and news about Marvel’s Runaways project.